Where Have All the People Gone? (1974) - A Solar Flash Motion Picture That's Food For Thought

A strange series of solar flares proves fatal for inhabitants of the Earth, except for the fortunate few who are somehow immune to the effects. Animals go insane and human beings turn to white powder, leaving behind only empty clothing. A handful of survivors attempt to rebuild their lives on the depopulated Earth.

Director: John Llewellyn Moxey
Writers: Lewis John Carlino, Sandor Stern
Starring: Peter Graves, George O'Hanlon Jr., Kathleen Quinlan, Verna Bloom, Michael-James Wixted, Noble Willingham
Producers: Charles W. Fries, Gerald I. Isenberg
https://www.imdb.com/title/tt0072400/